In his short story "Crabs on the Island" (1958) Anatoli Dneprov speculated on the idea that since the replication process is never 100% accurate, leading to slight differences in the descendants, over several generations of replication the machines would be subjected to evolution similar to that of living organisms.
•
Advanced Automation for Space Missions, edited by Robert Freitas, to produce a detailed proposal for self-replicating factories to develop lunar resources without requiring additional launches or human workers on-site.